Existing coffee makers are, for example, filter coffee makers and espresso machines. In the case of filter coffee makers, an amount of ground coffee is placed in a filter, after which hot water is poured onto the ground coffee. Upon the water passing the ground coffee, the ground coffee is extracted and a coffee beverage is obtained, after which the coffee beverage, also referred to as filter coffee, flows through the filter while the coffee residues are left behind in the filter. It is customary for the hot water to flow through the ground coffee and the filter with the aid of gravity. After the hot water that corresponds with the amount of desired coffee beverage has been poured out over the ground coffee and has passed through the filter, the filter, at least if it is a disposable filter, can be thrown away with the ground coffee residue. Such a disposable filter typically consists substantially of paper. Also known are filters that are designed to be used more than once. After use, these filters are, for example, cleaned, so that they can be filled with a next portion of ground coffee for preparing new coffee beverage with the same filter.
In coffee making by means of espresso machines, also a filter is provided for holding an amount of ground coffee. Here, under a relatively high pressure, hot water is forced through the ground coffee and the filter. The coffee beverage thereby obtained is generally relatively thicker than filter coffee and typically has a stronger concentration of coffee extracts than filter coffee, at least, given a comparable amount of ground coffee and supplied water. Typically, a metal filter is used.
Also, coffee beverage can be obtained in a known manner with the aid of a percolator. In certain machines, such as, for example, the Senseo® coffee machine of the producers Douwe Egberts® and Philips®, for example a paper disposable filter and a metal filter holder are used. Further, instant coffee is known, where coffee concentrate or freeze-dried coffee is dissolved in hot water. In this latter method, no filter at all is used.
If a relatively long time has elapsed between the grinding of the coffee beans and the preparation of the coffee beverage with the ground coffee, there is a chance that a part of the flavor and aromas given by coffee beans is lost. Without wishing to be bound to any theory, it may be that the larger total surface of the particles of the ground coffee together, compared with the joint surface of unground coffee beans of the same weight, causes relatively more exchange between the surface and the ambient air than the total surface of the coffee beans, which can adversely affect the taste and the odor of the coffee beverage. For that reason, in current machines with grinders, the coffee beans are ground a short time before the preparation of the coffee beverage.
Incidentally, it may also be that flavors and odors connected with the coffee beans may be lost or diminish when unground coffee beans come into contact with ambient air for a long time. Generally, for that reason coffee beans and ground coffee are packaged in airtight and/or vacuum packages.
Certain coffee machines may be provided with grinders that are integrated in the coffee machine. Also, such coffee makers may be provided with coffee bean holders for feeding the coffee beans directly from the coffee bean package. Through operation of the coffee making apparatus, a part of the coffee beans from the coffee bean holder is ground, for the purpose of preparing a coffee beverage with this ground coffee. For example, the grinder is directly operated by pressing a button, whereby, for example, the number of times the button is pressed, or the length of time of pressing the button, can determine the amount of ground coffee. In automatic coffee makers with grinders, the amount of coffee beverage and the strength of the coffee beverage can be pre-selected and/or pre-set, in which case on the basis of the selected strength a dose of beans is supplied from the holder to the grinder, so that an amount of coffee is obtained that, together with the predetermined amount of water, can result in a desired amount of coffee beverage of a desired strength.
Disadvantages of the above-mentioned principles can be that an amount of coffee beans is present in the coffee maker for a long time before it is ground, as a complete pack of coffee beans is emptied into the coffee bean holder. This can adversely affect the taste and odor of the coffee beverage prepared with these coffee beans.
Also, in and around the grinder of existing coffee makers there are typically residues left of the preceding grinding runs. Study has shown that in conventional grinders typically 3-10 grams of one or more preceding grinding runs are left behind in the grinder. These remainders of a previous grinding run may subsequently be entrained in a new grinding run, which can affect the taste of the coffee beverage. Moreover, if the coffee maker is filled with new coffee beans whose taste differs from the previous filling, the remainders of the previous filling may possibly be mixed with the ground coffee of the new coffee beans, so that not the desired taste inherent to the new coffee beans can be obtained. This may be disadvantageous in particular if the user regularly wishes to change the type of coffee beans. In conventional coffee makers, the user can circumvent this problem only by dosing the coffee bean holder in each case with a small amount of coffee beans. A disadvantage involved here, however, is that the coffee bean package then is not entirely emptied into the coffee maker and is left partly filled, so that the remaining coffee beans come into contact with ambient air. Typically, the coffee beans then are stored in the meantime in a separate, preferably airtight holder, such as an airtightly closable pot or tin. These holders, however, can take up relatively much space.
In the current state of the art, after grinding and making the coffee beverage, either ground coffee is left behind in the coffee maker or coffee beans are left behind in the coffee maker, or the coffee bean package is not emptied entirely and coffee beans remain behind in the package, or separate coffee bean holders are used. There is no system that allows regularly changing taste of freshly ground coffee in an efficient and convenient manner.